i went from 42x16 to 44x16 and it was a perfect step up. 3 gear inches or so, enough to feel the difference and help the top end but still climbable. To me this gear range(70-74 inches) is the most versatile, i tried 48x16 for a bit but hated life in headwinds or longer uphills. 48x18 falls right in the sweet spot too.